This disclosure relates generally to online systems, and in particular to joint modeling of user and content scores based on third party data.
Certain online systems, such as social networking systems, allow their users to connect to and to communicate with other online system users. Users may create profiles on such an online system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Because of the increasing popularity of these types of online systems and the increasing amount of user-specific information maintained by such online systems, an online system provides an ideal forum for third parties to present content to online system users.
In some cases, after a target user is presented with content by the online system from a third party system, the target user may subsequently perform various actions with the third party system that may not be known to the online system or detectable to the online system. With the information regarding the actions and other activities performed by the target user at a third party system, the third party system may have a large database of information regarding the logged actions and other characteristics of the target user. This additional data from a large number of users may provide the ability to better determine which users respond best to which type of content that is presented to those users. However, the online system does not have access to this data to use in selection of third party content to provide to user, nor a reasonable way to use this in ranking of content for users.